The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 12, 2000
Filed:
Feb. 06, 1998
Mitsubishi Materials Corporation, Tokyo, JP;
Abstract
A digital communication method and system wherein in response to input 3-bit data, a phase and amplitude of a carrier signal are controlled so that a symbol at a given time is located at one of allowed signal points depending on the content of the symbol. The allowed signal points include six signal points where a phase shift equal to .+-..pi./4, .+-.2.pi./4, or .+-.3.pi./4 occurs relative to the signal point at which the immediately previous symbol was located and where the amplitude is equal to a first level, and also include two signal points where a phase shift equal to .+-.2.pi./4 occurs relative to the signal point at which the immediately previous symbol was located and where the amplitude is equal to a second level lower than the first level. The digital communication method and system allows for a transmitter which does require a high-performance power amplifier, and a simplified receiver circuit. In addition, high-speed transmission can be achieved without expanding the bandwidth and high-reliability transmission is possible even in an environment having bad radio wave propagation as is the case in mobile communication.